Increased runoff in Missouri caused slight elevation of haloacetic acids in city water; no public health risk
Great Falls residents received notices in their utility bill of a slight increase in the level of haloacetic acids, HAA5 during the second quarter of 2018, which was April-June.
There is no risk to public health, according to city officials. The notification is required by the U.S. Environmental Protection Agency.
Wayne Lovelis, supervisor at the city’s drinking water plant, said that the city is required to monitor drinking water for specific contaminants on a regular basis and the tests for HAA5 are done quarterly with a maximum level of 60 micrograms per liter. The test results for the second quarter showed a level of 60.5 micrograms per liter at one of eight sample locations.
“It’s been an issue for quite a few systems in Montana this year,” Lovelis said.
HAA5 is a byproduct of organic material interacting with the chlorine used to treat drinking water.
Lovelis said last summer’s wildfires created a significant amount of organic material that was washed into the rivers, plus the heavy snowpack and early thaw caused a higher than normal amount of organic material in the river.
That organic material reacts with the chlorine creating the HAA5. Lovelis said that research has found that drinking an elevated amount of HAA5 over many years has caused cancer in some people, but it’s not a public health concern in this case since it’s a small amount and the issue is being resolved.
Normally, the turbidity, the suspended material in the water, in the Missouri River in Great Falls is 14-18 nephelometric turbidity units during the spring months.
“It was a pretty dirty river during that time,” Lovelis said.
It’s gone back to normal for the most part. As the NorthWestern Energy crews complete repairs on the dam it’s not causing many issues for the water plant unless the river continues to drop and the system will pick up more silt, causing some added work on the treatment side but has no impact on the drinking water.
If you have specific health questions, Lovelis recommends contacting your health care professional.
The city checks for other contaminants on a monthly basis and when there is a public health hazard, the city immediately notifies the health department, Montana Department of Environmental Quality and the public.